The Yukon River Inter-Tribal Watershed Council and the U.S. Geological Survey developed a water-quality monitoring program to address a shared interest in the water quality of the Yukon River and its relation to climate. This report contains water-quality data from samples collected in the Yukon River Basin during water years 2006 through 2008. A broad range of chemical analyses from 44 stations throughout the YRB are presented. On August 8, 2009 the USGS signed a Memorandum of Understanding with the Yukon River Inter-Tribal Watershed Council representing the culmination of 5 years of dedicated efforts to forge a working collaboration and partnership with expectations of continuing into the foreseeable future. The Memorandum of Understanding may be viewed at http://www.usgs.gov/mou/docs/yritwc_mou.pdf.